Concentration of ores



Patented, Aug. 3, 1 926.

JAMES L. STEVENS, OF HAYDEN, ARIZONA.

concnnrnarron or onns.

Ho Drawing.

" This invention relates to the concentration of ores, minerals, and the like, by flotation,

and has for its object the provision of certain improvements in the flotation processes, 5 and more particularly the froth flotation processes.

The present invention discovery relating to a mixture of certain chemical substances, whereby an effective flotation reagent is produced. I have found that the reagent produced by the mixture has marked selective action on sulphide minerals, and has also shown a marked tendency to recover oxidized metalliferous minerals, when used as a flotation agent in the customary flotation processes. My investigations indicate that the reagent, here in. described; is somewhat lacking in frothing-prop erties when used in the minimum amounts required for efle'cting the concentration of the minerals by flotation, so that a suitable frothing agent, such as pine oil, or the. like may advantageously be used in conjunction therewith in carrying out the flotation operation. However, this agent does possess some frothing properties in itself, and when used in larger amounts the flotation operation may be successfully caris based upon a 3 frothin" agent.

The otation reagent of the present invention is the. resultant compound obtained from the mixing of certain higher alcohols (for example those contained 1n fusel oil), carbon bisulphide, and. alkali, (such as potassium hydroxide) with or without ;water. In the preparation, the method and sequence of adding the chemicals may be varied. However I prefer to form an a saturated solution) and add this to a mixture of fusel oil and carbon bisulphide.

' In preparing the reagent of the present invention (using potassium hydroxide as the alkali), I may use 3&5 parts by weight of carbonfbi-sul hid 20 parts by weight of fusel oil? an 45. -parts by weight of a saturated solution of potassium hydroxide and water. These proportions correspond to two molecular equivalents of carbon bisulphi'de, one molecular equivalent of fusel oil, and two molecular equivalents of potassium hydroxide, assuming a mean molecular weight of 88 for fusel oil. .However I do not limit my clalms to the use of these definite proportions of the chemicals herein ried out without the use of pine oil or other impurities as may be ample,

aqueous solution of the alkali (preferably of carbon bisulphide.

Application filed August 2a, 1924. Serial No. 733,853.

named as I have found that by varying the quantities of the chemicals used for example by using l t parts by weight of carbon bi-sulphide, 17 parts by weight of the. fusel oil, ancl 39parts' by weight of the saturated aqueous solution of potassium hydroxide, I have obtained a similar product possessing similar flotation properties. These latter proportions correspond to three molecular equivalents of carbon bi-sulphide, one molecular equivalent of fusel oil, and two molecular equivalents of potassium hydroxide. While the above proportions are given as possible examples, I do not wish to limit my invention to the use of any definite quantity of any of the chemicals herein named as it may be necessary to use larger proportions of the carbon bi-sulphide and alkaliv in order to ensure complete reaction and combination of. at least two molecular equivalents of carbon bi-sulphide and at these two molecular equivalents of alkali with each molecular equivalent of higher alcohol in the reaction product. This is due to fact that these chemicals may in some cases contain impurities and should therefore in such cases be used in excess to ensure the dcsiredcombination, and alsoto furnish sufficient excess toreact with such formed in the product itself and still leave sufficient to react in the desired proportions in forming the compound.

The proportions may however, be varied according to variations in constitution of the fusel oil or higher alcohols used, for exto 50 parts of carbon bi-sulphide and sufficient alkali to react. It will thus be seen that the proportions may be varied considerably and especially the relative. proportion This maybe due to the formation of products consisting of different mixtures of compounds, said compounds containing one, two, three or more molecules of carbon bisulphide and a sufficient number of molecules of alkali to react, namely, one, two, three or more molecules in combination, per molecule of alcohol. While I prefer to use a product .containing as nearly as may be the maximum amount of carbon bi'sulphide, namely, two or more molecular equivalents, I may use a product containing less than this amount of carbon bisulphide. An advantage of the use ofa compound containing from 15 to35 parts of fusel oil, 25

. or more of the same,

the maximum amount of carbon bisulphidc is that such a co pound has a more marked sulphidizing action on the ore and therefore renders the flotation of oxidized ores, while it also has an extremely effective selective action on sulphide minerals.

Any suitable apparatus and method of procedure may be employed in preparing my flotation agent: For example, the mixture of carbon bisulphide and fusel oil in any of the above-described proportions, may first be introduced into a suitable vessel, provided with mechanical or other agitating means, and with a removable cover or other means for removal of the solid product, and preferably provided with a reflux condenser for preventinglos's ofcarbon bisulphide or other volatile substance by volatilization due to the heat developed by the reaction. The desired amount of alkali solution may then be added and the mixture thoroughly agitated until reaction is complete, the length of time required varying with the proportions of tlievarious ingredients used, for example from 10 to 30 minutes or longer. In general the reaction proceeds quite rapidly without application of heat, and in fact with the development of considerable heatof-reaction. If, however, in any case, it is found desirable in order to hasten "the reaction, the vessel may of course be heated, any suitable means being provided for this purpose.

I do not limit my claim to the use of any one of the so-called alcoholic compounds contained in what is commonly known as fusel oil. For example, I have found that the fusel oil, used in the preparation of the flotation agent herein described, contains various alclphols of the bhigh distillation grou sue as r0 '1 ut l, amyl, and other alcohols. :Iii f zigt, I ha ve found that the fuse] oil, herein described, contains various alcohols distilling from 97 C. to 230 C. ny or all of the fractions distilling between the range of. 97 C. to 230 C. may be used in the preparation of the flotation reagent herein described.

I may refer in some cases to use only the higher 0 the alcohol constituents of fusel oil, for example. butyl, amyl, or hexyl alcohol or any alcoholic product containing one and having a boilin point, for example, between 117 and 157 and in particular, very good results may be obtained with the alcohol known as amylic alcohol.

I do not limit my claim to the use of potassium hydroxide as an alkali in preparing the flotation reagent of the present invention, as for example, I have found that other alkalies, such as sodium hydroxide, may be substituted for potassium hydroxide. v

The flotation reagent herein described is soluble in water and may be dissolved with agent more effective in 0.15, pounds of my flotation circuit water recovered commercial grade of water prior to adding the same to the ore pulp, or it may be added to the ore pulp either alone or in admixture with other agents for promoting theflotation, in any suitable manner, so that the distribution is thorough and uniform throughout the ore pulp. The mixture is then subjected to a flotation operation such as used in the customary flotation processes.

In applying the reagent herein described it may be added in solid form, or in solution with ivater and may be introduced into the tube mill in which the ore is being ground or it may be otherwise introduced into the ore pulp in any uitable way, as, for instance, mixing with the ore pulp just before it enters the flotation cell.

The amount of the reagent of the present invention, required for effecting the concentration of ores may vary somewhat, for example, in treating ordinary clean sulfides the amount may be varied from pound or less per ton of ore to approximately pound per ton of ore (that is calculated on the weight of the ore and not of the ore pulp). In treating mixed ore, such as ores containing sulfide and oxide metalliferous minerals, it is advisable to use a larger quantity than is required for clean sulfide ores.

I have used this flotation agent for the concentration of a refractory ortion of the ore from the mines of the I ay Consolidated Copper Company at Ray Arizona,'said portion of ore containing about 0.97% of copper of which about 0.26% was present as 0xide copper. Flotation of this ore product carried out as above described, using about agent with about 0.3 pounds of pine oil per ton of ore, resulted in concentration sufficient to reduce the tailings to about. 0.17% of copper. Itis characteristic of the invention that the froth obtained is easily broken up and part of the reagent may be recovered therefrom, so that it is available for use in the treatment of 11 further amounts of ore. -That is to say, the from the concentrates and even that recovered from the tailings, contains notable amounts of the reagent which can be thus returned to the 1 process with resulting economy in the amount required to be added for subsequent flotation operations.

I prefer to "employ the reagent of the present invention as a flotation agent in a neutral (that is non-acid) or alkaline pulp. However, if the ore pulp contains acid, or if acid is preliminarily added thereto, the freeacidshould not be present-to such an extent as to destrqly the effect of the compound during the otation operation. Any alkali such as caustic soda, soda ash, trona, lime, or the like, may be added to the ore pulp in order to make the pulp neutral or alkaline 'tation operation.

It will be understood, by "those skilled in the art, that the present invention is applicable to the treatment by flotation of vanous kinds of mineral mixtures, both naturaland artificial. In the appended claims I have accordingly employed the terms minerals and mineral pulp in a broad sense to include mineral products and all materials amenable to concentration or similar treatment by the flotation processes.

-While I have described herein the method of making the flotation agent used in my improved method of flotation, I do not claim this composition of matter per se, or the method of making the same in this application, as these form the su' ject matter of another patent application of even date herewith Serial No. 733,854, patented Feb. 3, 1925 No. 525,211.

What I claim is 1. The method of eflecting the concentration of minerals by flotation which comprises adding to the mineral pulp a flotation agent consisting of the reaction product of fusel oil, carbon bi-sulphide, and alkali, and subjecting the resulting mixture to a flo- 2. The method of effecting concentration of minerals by flotation which comprises adding to the mineral pulp a flotation agent consistin of the reaction product of higher alcohols aving a boiling point from 97 C.

r to 230 0., carbon bi-sulphide,- and; alkali,

and subjecting the resulting mixture to a flotation operation.

3. The method of effecting the concentration of minerals by flotation which comprises adding to the mineral pulp a flotation agent consisting of the reaction product of a higher alcohol having a boilingint between 117 and 157 0., carbon bisu hide,

and alkali, and subjecting the resulting mixture to a flotation operation.

4. The method of efl'ectin concentration of minerals by flotation W ich comprises adding to the mineral pulp a flotation agent consisting of the reaction product of amylic alcohol, carbon bisulphide, and alkali, and subjecting the resulting mixture to a flotation operation.

5. The method tion of minerals by flotation which comof effecting the concentra prises adding to the mineral ulp a flotation agent consisting of the reaction product of 15 to 35 parts of fusel oil, 25 to 50 parts of carbon bisulphide, and sufficient alkali to react with said other components, and subjecting the resulting mixture to a flotation operation.

6. The method of-efl'ecting the concentration of minerals by flotation which comprises adding to the mineral pulp a flotation agent consisting of the reaction product of one molecular equivalent of a higher alcohol at least two molecular; equivalents of carbon lei-sulphide, and suiflcient alkali to react with said components, and subjecting the resulting mixture to a flotation operation.

7. The method of eflecting the concentration of minerals by flotation which comprises adding to the mineral pulp a flotation agent consisting of the reaction product of one molecular equivalent of a higher alcohol, at least two molecular equivalents of carbon bi-sulphide, and at least two molecular equivalents of an alkali, and subjecting the resulting mixture to a flotation operation.

In testimony whereof I have hereunto subscribed my name this 12th day of August 1924.

JAMES L. STEVENS. 

